Palladium-catalyzed condensation of symmetrical diaryliodonium salts with phenylacetylene in aqueous media

Abstract

liarities of the effect observed for birefringence (the non-quadratic dependence of the effect, exceeding the molecular effect by 4 orders of magnitude), note that it is proportional to the magnetic anisotropy of supramolecular structures AZ, at least a weak magnetic field. The molar constants of the effect of magnetic birefringence 3 mP 0 ~ AczAz approximated to a zero magnetic field are equal to 6.3 9 10 -11, 7.3 9 10 -11, 1.5.10 -7 cm 3 mo1-1 for La, Gd and Dy derivatives, respectively. The similar chemical properties of rare-earth ions, along with the IR and N M R data for solutions and for the condensed phase suggest that the solutions of the complexes studied have the same structure, and, hence, the same anisotropy of electronic polarizability (Am) of their objects. Thus the ratio of the anisotropy for the magnetic susceptibilities of the associates, and, in the approximation of axial symmetry, of the remaining complexes (AXm) is approximately equal to the ratio of the mP 0 constants: AXm(La)/AXm(Gd)/AXm(DY ) = 1/1.2/2.4" 103 . Analogous results were obtained for solutions of the complexes in chloroform and benzene. The liquid crystal complexes of diamagnetic lanthanum and paramagnetic (S = 7/2, Pelf = 7.9 M.B.) gadolinium (in S state), which have similar compositions and structures, possess magnetic anisotropy typical of mesogenes. The paramagnetic complex of Dy is characterized by magnetic anisotropy, significantly exceeding the anisotropy of known organic and metal-containing mesogenes.